1. Field of the Invention
This invention relates to a method of making polymeric matte bead particles for use in photographic elements, and more particularly to a method of making matte bead particles having improved adhesion in hydrophilic colloid layers.
In the preparation of photographic elements, there is an ongoing need to utilize polymeric matte particles having a narrow particle size distribution, while at the same time, having improved adhesion to the hydrophilic colloid layer containing the matte particles during processing of the film. That is, the matte particles should be tightly bound to the binder which, in addition to the matte, forms a layer of the photographic element.
2. Description of Related Art
Polymeric particles are typically made by dispersing polymerizable liquid monomer droplets in a continuous aqueous medium. Solid polymer particles are formed by reacting the monomer to a solid polymer. A surface active material is included to stabilize the dispersion. Lyophilic polymers including starch, natural gums, polyvinyl alcohol, gelatin, and the like have all been used as stabilizers for the polymerizable liquid monomer droplets. This technique is set forth in U.S. Pat. No. 2,932,629, which is representative for preparing polymeric particles.
It has been found, however, that the inclusion of hydrophilic colloids generally and gelatin, in particular, when added to monomer droplet dispersions in water for the purpose of stabilizing the monomer droplet dispersions, produces particle size distributions that are broad and not reproducible. Also, the mean particle size is affected by the amount of hydrophilic colloid present and the amount of hydrophilic colloid that can be used is limited by the rheology of system.